Sealing closure for containers



De@- 9 3952 G. A. wElsGERBER 2,(,520939 SEALING CLOSURE FOR CONTAINERSFiled Sept. 9, 1948 lai. T1 -5- 50 Msi/1L Patented Dec. 9, 1952 SEALINGCLOSURE FOR CONTAINERS George A. Weisgerber, Havertown, Pa., assigner toJohnson & Johnson, a corporation of New Jersey Application September 9,1948, Serial No. 48,346

4 Claims. -(Cl. 215-40) This invention relates to -readily removablesealing closures for containers. It is especially useful for glassbottles containing lotions, medicaments or chemicals Where it isimportant to prevent leakage in transit or to prevent substitution oradulteration. Therefore the invention will be described, forillustration only, as applied to such use.

It is customary to pack liquids in bottles hav- -ing a screw cap linedwith a resilient and impervious disk or gasket which seals the bottlewhen the cap is screwed on. It has also been proposed to preventtampering and leakage in transit and the like by sealing the bottle witha diaphragm or memb-rane adhered to the mouth of the bottle in additiont-o the cap. When the bottle is first opened the membrane is broken orremoved and thereafter the bottle is closed by screwing von the cap,relying on the resilient disk which is then called a re-sealing disk.Such seals that have come to my attention have been unsatisfactory inseveral respects, particularly in the case of glass bottles containingoils or medicaments vfor personal use, for example, because the sealingmembrane was difficult to remove, or because bits of the membrane oradhesive yor both adhered to the bottle, making it unsightly andcreating suspicions of uncleanliness.

My invention seeks to overcome these and other disadvantages of knownseals by providing an improved seal which can readily and economicallybe attached, which is secure until it is forcibly removed, but yet isreadily removable by the user, and which leaves the container clean whenremoved. It is particularly an object to provide such a seal which iscompletely effective with glass containers. Other objects and advantageswill be apparent in the description and claims.

In the drawings:

Fig. 1 is an exploded perspective view of a bottle and screw capembodying one form of my invention;

Fig. 2 is a section of the cap;

Fig. 3 vis a perspective of one modified form of a portion of myimproved seal;

Fig. 4 is a perspective Yof a second modified form; and

Fig. 5 is a magnified edge view of a composite seal embodying a thirdmodified form.

A container lll, preferably of 'dielectric material, especially glass,has the usual opening or mouth l2, in a neck or wall I4 which includesan end surface I6 surrounding the mouth and disposed in a plane. Thissurface is preferably fiat and relatively broad. The usual cap I8 may beused. It and the neck may be provided with screw threads, or any otherknown or suitable means for mechanically holding the cap against the endsurface I6. The cap is preferably formed of any suitable dielectricmaterial such as any of a wide variety of molded plastics. Any suitableresilient, impervious sealing disk 20, inert to the material to be putin the container is secured in the cap.

My improved seal includes, for example, a film 22 of material which willadhere to the container, especially to glass -and is inert with respectto the contents. It also includes a unitary sealing membranecollectively denoted -by 24, inert to the contents and adapted to adhereto the lm 22. When the cap is screwed on and the adhesive film is-activated the membrane is sealed to the bottle and the cap can becomeloose or can be removed, leaving the bottle sealed. This preventsleakage in transit, and serves to detect opening of t-he bottle byunauthorized persons. To facilitate detection the membrane may beprovided with the bottlers signature, and an adhesive is used which,when the seal is once removed, cannot be readily resealed to the bottle.

The materials of the container, the film 22 and the membrane 24 are sorelated to each other that the strength of the adhesive bond between thefilm and the container is less than the internal strength or internalcohesive bond within the lm and less than the strength of the adhesivebond between the nlm and the membrane. The adhesive bonds within thecompositeV membrane 24 are also greater than the lm-to-glass bond. Alsothe strength of the bond between the film and the glass is such as topermit forcible although leasy lrem-oval of the membrane with afingernail. This .arrangement .assures that when any adequate attempt ismade to remove the seal, the lm leaves the glass cleanly, and neitherthe membrane nor the lm will split itself. rIhis effectively preventsany bits of membrane or of adhesive film from remaining on the bottle.

When the sealing membrane and film have thus been removed and discarded,the bottle can be capped and yclosed in the usual way, the reseal liner20 preventing leakage as long as the cap is tight.

The results described above can be effected in a simple and economicalmanner which can be performed quickly on a production line.

Preferably all of the materials heretofore described are dielectric, anda disk of metal foil is placed in or on the sealing membrane. The film.22 is of heat-sealing or thermo-adhesive material, by which is meantmaterial which becomes adhesive at high temperatures. The film andmembrane are placed in position and the cap is screwed on tight. Theassembly is then heated in any suitable manner, preferably by placing itin a high frequency dielectric field which rapidly heats the metal disk.This heats the film 22 by conduction until the film becomes adhesivewhile under the pressure of the cap. The bottle is then removed from thefield and upon cooling the nlm is adhered both to the bottle and to themembrane, as described.

The membrane may be formed of a heat-sealing resin sheet 26 (hereindesignated Resin A), which may, if desired, have a somewhat highersoftening temperature than the softening temperature of the film 22(herein designated Resin B) and a sheet of metal foil 28, such as thinaluminum. These layers are sealed into a'unitary assembly in anysuitable known way as by solvent spreading the sheet 216 onto the foilte secure adhesion. The high softening temperature of the sheet 26prevents loosening the bond ibetWeen that sheet and the metal foil underthe relatively low temperature attained during .the sealing operation,Vbut permits the sheet to .be adhered to the metal at .a vhighertemperature when the membrane is manufactured. 'The membrane may befaced on its upper vsurface vby a layer of stiff paper 30 which may beadhered to the foil-in any suitable way. This prevents damage to thefoil layer when the cap is screwed on. The strengths of the bondsbetween the foil and both layers of the membrane exceeds the strength ofthe film-to-glass bond to prevent splitting of the membrane duringremoval of the seal.

In Fig. 1 the adhesive film is schematically represented. It may beformed ,and placed in a variety of ways. It may be a Washer .22 of castfilm, as indicated in Fig. l, 'or 'it may ybe a disk 22a of cast film asindicated in Fig. 3. Preferably it is a dried heat-sealing deposit 22hfrom a solution of the adhesive applied beforehand to the bottle (Fig.4).

In still another form of the invention as indicated in Fig. 5, AI mayform a sandwich of the two sheets 26 and 30 and `the inner layer 28 ofmetal foil. To the lower surfaceof this menibrane I apply an adhesivenlm A222e of heatsea1 ing resin B. This film may be applied by solventcoating, by heating .and pressing a cast film or in any suitable way..Preferably the film 22e is distinctively colored to facilitate assemblyright side up. In any case and especially where the modification ofFigs. l, 3 or 5 is used I may grind the surface lf3 is increase theadhesion of the film to the glass.

As materials for Resin A, I `may use polyvinyl butyral or any widevariety of known vinyl resins, with or without a suitable plasticizer,the molecular weight of the vinyl polymer and the kind and proportion ofthe plasticizer being regulated to give the desired thermoplastic andadhesive properties, as known in the art. In particular, I may use aresin designated in the trade as VMCH and manufactured by Carbide andCarbon Chemicals Corporation, New York, New York and said to be acopolymer of vinyl vchloride .and vinyl acetate having approximately 85%to 88% vinyl chloride and being copolymerized with approximately 1% ofmalec acid. I may use a film deposited by evaporating a l to 20%solution of VMCH in methyl ethyl ketone or other suitable solvent.

For the heat-sealing film or resin B, I may use as in Fig. 4 a coatingsolution, which may be applied to the end surface I6 by roller coatingwith subsequent evaporation of the solvent, such a solution consistingof any of the following:

Example I Per cent VMCH 1.7 VYHH 11.0 Paraplex G-25 (plasticizer) 1.3Methyl ethyl ketone 86.0

Example II Per cent VMCH 3.0 VYHH 12.0 Dioctyl phthalate (plasticizer)1.5 Methyl ethyl ketone 83.5

Example III Per cent VMCH 3.0 Saran F--120 (200 centipoises) 8.0Paraplex (J1-25 1.2 Methyl ethyl ketone 87.8

Example IV Per cent VYHH '6.0 Saran F-l20 (200 centipoises) 6.0 ParaplexACir-25 '0.5

Methyl ethyl ketone 87.5

vExample V Per cent Polyvinyl butyral (high viscosity) 12.0 Dioctylphthalate 1.5 Ethanol 86.5

In these examples, VMCH is the vinyl resin identified above, VYHH is thetrade ydesignation of a Vinyl resin manufactured by Carbide and CarbonChemicals vCorpora-tion and said -to Lbe a thermoplastic copolymer ofvinyl chloride and vinyl acetate having approximately to 88% vinylchloride and an average lmolecular weight of 10,000 (Staudingerviscosity method). Paraplex G-25 is a trade name applied lby ResinousProducts and Chemical Company, Philadelphia, Pennsylvania, to aplasticizer identified by them only as -a resinous polyester. Saran isthe generic name for a series of polymers -and copolymers of vinylidenechloride usually with vinyl chloride with or without acrylonitrile.Saran F-.120 is the trade designation applied by Dow Chemical Company,Midland, Michigan, to a copolymer of vinylidene chloride andacrylonitrile vhaving in a 20% solution in methyl ethyl ketone aviscosity of from 40 to 8000 centipoises (Brookfield 25 C).

rThe invention claimed is:

1. A-container having an opening and comprising in combination an endsurface surrounding the opening, a wall surrounding the end surface, acap, means on the cap and wall adapted to cooperate to urge the captoward the end surface, and a sealing membrane for closing the opening,the membrane including a heat-sealing adhesive film in contact with theend surface and an electrically conductive layer in thermal contact withthe adhesive film.

.2. A container having an opening and com prising in combination an endsurface surrounding the opening, a wall surrounding the end surface, acap, means Aon the cap and wall adapted to cooperate to urge the captoward the -end'surcooperate to urge the cap toward the end surface, 10

and a sealing membrane for closing the opening, the membrane including aheat sealing adhesive lm in contact with the end surface, said a-dhesivefilm having a stronger bond to the membrane than to the end surface, andan electrically conductive layer in thermal contact with the adhesivelm.

4. A glass container having an opening and comprising in combination anend surface surrounding the opening, a Wall surrounding the end surface,a cap, means on the cap and wall adapted to cooperate to urge the captoward the end surface, a sealing membrane for closing the opening, themembrane including heat sealing adhesive lm in contact with the endsurface,

said adhesive lm having internal strength greater than the strength ofthe adhesive bond between the lm and the container, and the adhesivebond between the lm and the membrane being greater than the strength ofthe adhesive bond between the film and the container, and a metal sheetin thermal contact with the adhesive film.

GEORGE A. WEISGERBER.

REFERENCES CITED The following references are of record in the iile ofthis patent:

UNITED STATES PATENTS Number Name Date 1,304,304 Garhart May 20, 19191,382,051 Beavers et a1 June 21, 1921 1,603,057 Wright Oct. 12, 19261,731,195 Ellis Oct. 8, 1929 1,916,977 Gutmann July 4, 1933 1,966,273Waring July 10, 1934 2,004,079 McManus June 4, 1935 2,013,119 WarthSept. 3, 1935 2,026,937 Eisen Jan. 7, 1936 2,077,992 Eisen Apr. 20, 19372,233,160 Eisen Feb. 25, 1941 2,326,722 Burkardt Aug. 10, 1943 FOREIGNPATENTS Number Country Date 367,366 Great Britain Feb. 18, 1932

